Dihydronepetalactone is a useful compound that has been shown to have insect repellent properties [see, for example, Jefson et al, J. Chemical Ecology (1983) 9; 159-180; and WO 03/79786]. Methods for the production of dihydronepetalactone are known from sources such as Regnier et al [Phytochemistty (1967) 6:1281-1289]; Waller and Johnson [Proc. Oklahoma. Acad. Sci. (1984) 64:49-56]; and U.S. Pat. No. 7,067,677 (Manzer). Those methods have, in general, described the production of mixtures comprising isomers of dihydronepetalactone by contacting purified nepetalactones with hydrogen in the presence of a catalyst.
A need nevertheless remains for a method for converting mixtures comprising trans-cis nepetalactone and cis-trans nepetalactone to dihydronepetalactone with limited formation of the less desirable by-product puleganic acid.